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Re: scope of _:existentials in N3Logic?

From: <jos.deroo@agfa.com>
Date: Mon, 1 Mar 2010 22:36:32 +0100
To: yves.raimond@gmail.com
Cc: connolly@w3.org, Graham Klyne <GK-lists@ninebynine.org>, public-cwm-talk@w3.org
Message-ID: <OF06F82202.CAB57557-ONC12576D9.0073EC80-C12576D9.0076B387@agfa.com>
Hi Yves,

The euler.yap code is tuned for Yap and for a while we had a clone for SWI
namely http://eulersharp.sourceforge.net/2006/02swap/eyes.pl
When comparing eyes.pl performance with
the numbers are

   10     0.000 sec
  100     0.030 sec
 1000     1.920 sec
10000   435.501 sec

hence about 1000 times slower than eye for depth 10000 and I guess
more than 1 million times slower than eye for depth 1 million.
This is IMHO mainly due to yap's really nifty demand driven indexing

Today Yap is also moving closer and closer to SWI compat

That said, the scope of _:existentials in N3Logic is indeed worthwile to 
tested independently and thanks for your plan to have a deeper look :-)

Kind regards,

Jos De Roo | Agfa HealthCare
Senior Researcher | HE/Advanced Clinical Applications Research
T  +32 3444 7618

Quadrat NV, Kortrijksesteenweg 157, 9830 Sint-Martens-Latem, Belgium

Yves Raimond <yves.raimond@gmail.com> 
03/01/2010 07:10 PM

connolly@w3.org, Graham Klyne <GK-lists@ninebynine.org>, 
Re: scope of _:existentials in N3Logic?

Hello Jos!

Hi Yves, 

Let me first say that I really like your Henry work esp. the N3 DCG. 
Also thanks to Graham for sharing his Swish experience. 

As you say, in Euler we can use Skolem functions via the e:tuple builtin 
but in the latest Euler yap engine we don't need the Skolem functions 
anymore, we use a "Skolem machine" and "labelvars" instead, 
see the predicates sem/1, sem/4 and labelvars/4 in the code at 

Wow - at first glance that looks amazing! I really like the idea of using 
functors for variable quantification - I will definitely take a deeper 
look into it! Did you try that code with SWI already, or does it only run 
on Yap?

Many thanks,
Received on Monday, 1 March 2010 21:37:07 UTC

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